With the advent of improved electronic hardware technology, personal electronic devices have become smaller and more portable. As a result, users frequently carry their portable electronic devices to a variety of venues, especially to publicly accessible sites. Unfortunately, such public venues, including restaurants, public transportation such as busses, and stores, are also accessible to those interested in stealing personal property, such as personal electronic devices. Theft and loss of personal electronic devices, such as smartphones, is sadly frequent. Many current portable electronic devices include security features intended to prevent anyone, except the legitimate owner, from using them and accessing potentially sensitive information.
A common security method is to present the user with a security interface comprising a keypad or similar display, and requesting an input that, in theory, only the legitimate user would know. However, this security feature may not be sufficient. For example, a dedicated thief may secretly observe the user while he or she enters the security code, and memorize the sequence of hand or finger gestures required to unlock the device. Alternatively, the thief, once in possession of the device, may use various means to visualize the finger positions on the touch screen based on the build-up of oils left on the touch screen by the user's fingers. The assumption behind this technique is that the most common touch input on the screen would be the user's security code. If the security interface is a keypad graphic located at a standardized position on the screen, and having a standardized layout, the user would touch the screen at the standardized locations corresponding to the security code. As a result, more finger residue would build up on the touch screen at the positions corresponding to the security code (or minor permutations of the code).
It would, therefore, be useful to provide an improved security interface for a personal electronic device featuring a touch screen input.